A strong earthquake shook central Japan on Saturday night , injuring dozens of people and destroying homes in a well-known ski resort , authorities said .

Reports differed on the intensity of the quake , centered in a remote mountainous area of Nagano prefecture . The Japan Meteorological Agency reported it was magnitude 6.8 ; the U.S. Geological Survey -LRB- USGS -RRB- said it was magnitude 6.2 .

One of the hardest hit areas was the skiing village of Hakuba , where at least seven housing and storage structures collapsed .

Seven of the 39 people hurt in the quake suffered serious injuries , Nagano prefectural police said .

Japanese television stations carried images of landslides that had cut off roads and railroads , as well as flattened houses and warped highways .

More than 300 rescue workers were deployed to search for people trapped in collapsed homes . Authorities said the rescue operation was completed .

No electric facilities , including nuclear power plants , were damaged , the Tokyo Electric Power Co. said via Twitter Saturday .

Aftershocks followed the main quake Saturday night , including one measured at magnitude 4.1 , the Japan Meteorological Agency said .

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Thirty-nine people are injured , seven of them seriously , police say

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The quake destroys homes in a popular ski resort in Nagano prefecture

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No electric facilities were damaged , power company says

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Quake reported at 6.8 magnitude by Japanese agency ; USGS says it was 6.2